A Microbiological Assay Technique for Panto- Thenic Acid with the Use of Proteus Morganii”

Several methods for the assay of pantothenic acid have been reported in the literature. They have been based on the growth response of yeast (l), bacteria (2, 3), and chicks (4, 5) to the vitamin. The relative merits of these methods have been discussed in an earlier paper (3). In a previous publication (6) it was shown that pantothenic acid is one of the growth factors required by Proteus morganii. Subsequent experiments in which synthetic crystalline calcium pantothenate (Merck) was employed in a chemically defined medium indicated that the organism responded to exceedingly low concentrations of this substance; raising the calcium pantothenate level within limits resulted in a corresponding increase in growth. On the basis of this reaction to pantothenate a technique has been developed for its assay. Since the method possesses certain desirable features, its application to routine assays of pantothenic acid in natural materials may be warranted.